Cyberpunk 2077

While the achievement description does sound quite straightforward, the requirements are actually pretty strict. Using a revolver or pistol, you need to kill/incapacitate 3 enemies in under 4 seconds while in melee weapon range from each one when you kill them. In the majority of situations where this can be attempted, the time limit is not the issue so much as the distance you are from each enemy you kill. You need to be very close to each enemy, close enough that you'd be able to hit them with a melee weapon equipped. This is what can make this achievement challenging to happen naturally, because most likely at least one enemy is going to back away and move to cover, rather than all of them coming up close to you.

Because of that, the easiest way to unlock this achievement is to find a group of enemies in neutral territory. They can often be found standing around the side of the street, at various locations. I found a group of three enemies very close to each other out front of The Chapel in Pacifica, but anywhere that isn't a hostile area works fine. Since you're not in a hostile area, you can literally walk right up to enemies with your gun out and they don't react. If they're all standing, you may even be able to line up a double headshot, hopefully killing two enemies with a single bullet (as long as the second enemy isn't too far away to not count), and then you can quickly run up to the third and unload your clip into them. Once you do find a group that looks good to try this achievement on, definitely make a manual save before attempting it, so you can reload it and try again if need be (which you probably will need to, since enemies have a tendency to bob and weave when you're trying to shoot them up close).